Clinical diagnosis
Case 284
【Progress】
Two months later, he took contrast-enhanced CT depicting diffuse liver metastasis with massive portal tumor thrombus (Fig. 5). Then, the final clinical diagnosis was made portal vein tumor thrombosis.
【Discussion】
It is known that portal vein tumor thrombosis (PVTT) often occurs in advanced hepatocellular carcinoma (HCC) and rarely occurs in gastroenteric cancers. According to the Annual Report of the pathological autopsy cases in Japan, PVTT occurs in 1.2% of gastric cancers (1, 2).
The mechanism of causing PVTT is documented to be three routes; via direct invasion of gastric cancer to extrahepatic portal veins, such as right gastric, left gastric vein, short gastric veins and gastroepiploic vein; via metastatic lymph nodes invasion to adjacent extrahepatic portal branches; via intrahepatic metastasis to adjacent intrahepatic portal vein (3). AFP-producing gastric carcinoma might tend to invade to portal vein (4). When filling defect in portal vein exists adjacent lymph nodes or intrahepatic tumor, the diagnosis of PVTT might not be difficult. However, in the situation of without swollen lymph node and intrahepatic mass, PVTT can be sometimes difficult to differentiate from bland portal vein thrombosis. Thrombosis can occur in patients with cancer since tumor increase coagulopathy called as Trousseau’s syndrome which most often occur in patients with advanced pancreas cancer (5). It is described that positron emission tomography (PET) is useful for differentiation since stand uptake value (SUV) is significant higher in PVTT than bland portal vein thrombosis. Meanwhile, the feasibility of MRI for its differentiation is controversial. Experimental study reveals that ADC values of fresh thrombus within 3 days are more than 1.5 and a clinical study is reported to the possibility to differentiate them because ADC value of bland thrombus more than 1.5 and that of PVTT is less than 1.0 (7). However, a clinical study the ADC values of bland portal vein thrombosis and PVTT overlap, inducing hard for differentiation between them (8, 9). From literature review, when ADC value of feeling defect in the portal vein elevates more than 1.5 or more, it can be solidly judged bland portal vein thrombosis (7-9). But when ADC value of portal vein filling defect is less than 1.0, it cannot be evaluated whether it is bland portal vein thrombosis or PVTT (8, 9).
Our patient had underwent total gastrectomy 8 months before and thereafter, chemotherapy using TS1 for 6 months. Contrast enhanced CT and MRI depicted filling defect from gastric vein, main portal vein, left portal vein and P8 portal branch vein. T1WIMRI depicted high signal intensity corresponded to main portal vein and left portal branch vein, indicative of corresponded to bland portal vein thrombosis, although ADC value was less than 0.97 to 1.3. Two months later, enhanced CT using contrast medium depicted enlargement filling defect in main portal venin and diffuse intrahepatic hypo-vascular nodules, indicating intrahepatic diffuse metastases with PVTT. Retrospectively, as ADC value of one of the portal vein filling defects was less than 1.0, it might be better to have interpreted the possibility of malignancy.
【Summary】
We presented a seventy two-year-old male for exhaustion and mild fever. He had undergone total gastrectomy for advanced gastric cancer and thereafter chemotherapy for 4 months. Based on imaging findings which indicated filling defect in main portal vein and left portal vein on enhanced CT and high signal intensity on T1WIMRI corresponded to portal vein lesion, bland portal vein thrombosis was diagnosed. However, two months later, contrast-enhanced CT depict filling defect in main and left portal vein enlarged and diffuse intrahepatic hypo-vascular lesions, indicative of portal vein tumor thrombus and diffuse intrahepatic metastases. It is borne in mind that although it is rare, PVTT can occur in gastroenteric cancers, 1.2% in gastric cancer. PET might be better for differentiation between bland portal vein thrombosis and PVTT. Meanwhile, diffusion WIMRI does not rely upon for its differentiation because ADC values in clinical cases with bland portal vein thrombosis and PVTT overlap. However, ADC values are useful when they elevate more than 1.5, indicative of benign lesion, bland portal vein thrombosis.
【References】
1.The Japanese Society of Pathology (eds). Annual of the pathological autopsy cases in Japan. Aichi: Jinshikai; 1998.
2.Ishikawa M, Koyama S, Ikegami T, et al.: Venous tumor thrombosis and cavernous transformation of the portal vein in a patient with gastric carcinoma. J Gastroenterol 1995; 30: 529– 533.
3.Eom BW, et al. Survival analysis of gastric cancer patients with tumor thrombus in the portal vein。J Surg Oncol. 2012 Mar;105(3):310-5.
4.Araki T, et al. Portal venous tumor thrombosis associated with gastric adenocarcinoma. Radiology. 1990 Mar;174(3 Pt 1):811-4.
5.Dammacco F, et al. Cancer-related coagulopathy (Trousseau's syndrome): review of the literature and experience of a single center of internal medicine. Clin Exp Med 2013 May;13(2):85-97.
6.Yoshioka T, et al. Evaluation of 18F-FDG PET in patients with advanced, metastatic, or recurrent gastric cancer. J Nucl Med. 2003;44(5):690–9.
7.Ichiki M, et al. Experimental venous thrombi: MRI characteristics with histopathological correlation. Br J Radiol. 2012 Apr;85(1012):331-8.
8.Sandrasegaran K, et al. Usefulness of conventional MRI sequences and diffusion-weighted imaging in differentiating malignant from benign portal vein thrombus in cirrhotic patients. AJR Am J Roentgenol. 2013 Dec;201(6):1211-9.
9.Ahn JH, et al. Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis. Korean J Radiol. 2016 Jul-Aug;17(4):533-40
2022.11.30